Mercury or liquid contact switch



June 1953 l. SHAMAH 2,642,512

' MERCURY OR LIQUID CONTACT SWITCH Filed Jan. 5, 1951 2 Sheets-Sheet lIN VEN TOR. ISRAEL SHAMAH AT TORNE Y June 16, 1953 l. SHAMAH 2,642,512

\ MERCURY OR LIQUID CONTACT SWITCH Filed Jan. 5, 1951 2 siiets-sheet 295 INVENTOR.

ISRAEL SHAMAH operations Patented June 16, 1953 UNITED STATES PATENTOFFICE MERCURY OR LIQUID CONTACT SWITCH Israel Shamah, New York, N. Y.,assignor to Ismah Corporation of New York Application January 5, 1951,Serial No. 204,505

Claims. 1

This invention relates to mercury or liquid contact switches. r

' It is an object of the present invention to provide a mercury switchwherein there is incorporated within the switch a circuit-breaking-feature so that upon overload of a circuit including this switch, themercury is forcibly displaced from its position between contacts to aposition removed therefrom and retained thereat until the switch isagain tilted to its set posi- .tion.

from injury resulting from an electrical discharge and to makeunnecessary the delicate usually provided with mercury switches onfilling such switches with hydrogen gas and thereby to provide such aswitch wherein hydrogen is unnecessary and which provides a structurethat permits easy filling with hydrogen should the need for the hydrogenseem needed.

It is another object of the invention to provide a simple constructionand method of assembly of the parts of a mercury switch wherein thecontact terminals are extended into the mercury chamber through acovering element forming one end of the ceramic enclosure and vwhereinthe sealing of the unit is effected over the terminals to hold them inplace and to close off and insulate the end of the mercury switchelement.

It is another object of the invention to provide a mercury switchelement whereby the mercury chamber is set within the handle and formsan integral part thereof.

It is still another object of the invention to provide a mercury switchelement wherein contacts are provided on the end of the mercury elementand wherein these contacts slide over .arcuate fixed or stationarycontacts to which contacts for the individual elements are disposedabove and below the elements out of the way and so as not to giveinterference with the operation of other mercury elements.

, Other objects of the invention are to provide in mercury switches thatare of simple construction, easy to assemble, inexpensive tomanufacture, compact, has a minimum number of parts, capable of carryinga heavy load, fireproof, and eflicient in operation.

For other objects and for a better understanding of the invention,reference may be had to the following detailed description taken inconnection with the accompanying drawing, in which:

Fig. 1 is a perspective view of the mercury switch bearing the mercuryelement constructed according to one form of the present invention.

Fig. 2 is a vertical sectional view of the switch taken on line 2-2 ofFig. 1.

Fig. 3 is a side elevational view of the switch of Fig. 1 with portionsbroken away to show the mercury element and with the switch handleelevated to the on position.

Fig. 4 is an exploded perspective view of the switch assembly shown inFig. 1.

Fig. 5 is a fragmentary transverse sectional view of the mercury elementtaken on line 5--5 of Fig. 4.

Fig. 6 is a fragmentary side elevational view of a switch assemblyemploying a switch element adapted to be placed in three positions andwherein upon overload, the mercury is dis- I placed and retained in aremoved position within I Fig. 10 is an enlarged transverse sectionalview taken on line lfl-IO of Fig. 8 with the switch element being in theoff position.

Fig. 11 is an enlarged transverse sectional view of the switch elementin the on position and as viewed on line lll| of Fig. 9.

Fig. 12 is an exploded perspective view of the switch fuse element shownin Fig. 6.

Fig. 13 is a perspective view of a modified form of the invention withportions broken away to show the interior construction of the switch andwherein the contacts of the switch element are provided on the endthereof and are slidable over arcuate contacts fitted in the housing.

of one of the switch fuse elements used in the multiple unit switchassembly shown in Fig. 16'

with portions of the same broken away to show the interior constructionthereof and to show an adjusting screw for fixing the element to thegang shaft.

Fig. 18 is a perspective view of a -mercury switch having pig-tail wiresand without intervening friction contact parts.

Referring now particularly to Figs. 1 to 5, 2| represents a casinghaving a large recess 22 in which mercury switch element 23 is connectedfor tilting adjustment. The ends of the.

casing 2! are enlarged and are cut away respectively at 24 and 25 toreceive respectively contacts 26 and 21. The contact 26 fits in therecess 24 and a wire can be connected thereto by screw 26. This screw 28may enter hole 29 in the enlarged end of the casing 21.

The contact member 21 fits the recess 25 and will be projected along theopposite side of the casing 2 i. This contact strip 27 is held in placeby a screw 39 to which a wire can be attached and this screw enters ahole 3| in the recess 25. The respective contact strips 26 and 27 havedepressed ends 32 and 33 respectively adapted to seat in depressions 34and 35 respectively of contact strips 36 and 31 on the mercury switchelement 23.

The switch element 23 has an opening or chamber 38 therein that is linedwith ceramic material 39, such as porcelain, in the form of an openended box slidable into the opening 38 in the body of the element whenbeing assembled. The contact strips 36 and 31 extend along the oppositesides of the switch element body, preferably in grooves therein andtheir respective ends are bent around the end of the body and projectedinto the opening 38 and into the ceramic vessel 39 in spacedrelationship, as indicated at 4| and 42. A ceramic plate 43 has holestherein for receiving the ends 4! and 42 in such a manner as to holdthese ends in relationship relative to one another. The contacts 36 and3"! have the ceramic plate 43 and are made fixed by addingself-hardening cementitious material, as indicated at 44, such as a coldsetting phenolic, porcelain paste, or a bituminous sealer. The materialshould withstand the stresses and strains of heat. If desired, theentire assembly can be of molded construction with the porcelain partseither molded in or dispensed with, depending upon the load of thecircuit with which the switch is to be used.

The switch element body 23 has an integral handle portion 45 with sideshoulder formations 46 thereon engageable with spring wire portions 41on a mounting plate 48 which is secured to the front of the casingmember 2| by attaching screws 49 and 50. The shoulder formations 46respectively have sides angled with respect to one another and each sidecan fit in an intermediate portionv 5| of the spring wire retainingmembers 41, Fig. 4. By this spring wire retaining member and the seatingof the sides of thecollected in the pocket 6|.

shoulder formation 46 therein, the switch element will be retained ineither its off position, as shown in Fig. 2, or in its on position, asshown in Fig. 3.

The chamber 38 has a deposit of mercury 52 therein. When the switch isin the off position, as shown in Fig. 2, this mercury will be depositedin the forward end of the ceramic vessel 39, but upon the switch elementbeing pivoted to the on position, as shown in Fig. 3, the mercurydeposit 52 will lie in the rear end of the vessel 39 and will bridge thecontact portions 4| and 42 to establish an electric circuittherebetween. The entire assembly, by means of the mountin Plate 48 canbe fixed as a unit in the usual wall outlet or receptacle.

Referring now particularly to Figs. 6 to 12, there is shown a modifiedform of the invention wherein the switch element serves as a fuse forthe electric circuit governed by the switch. According to this form ofthe invention, 55 represents the switch element. This switch element hasa hollow portion 56 and an integral handle portion 51.

This hollow portion 56 provides for an opening 58 in which is disposed aspecially formed ceramic box having a bottom part 59 providing anabutment 60 and an inclined pocket 6| into which mercury 62 can becollected. On this same part 59 is a recess 63 with a central barrier64. Into this recess there is extended inwardly bent ends of contacts 65and 66 for engagement with a mercury body. Mercury may lie on theopposite side of the barrier 64 and over the contact ends withoutestablishing a circuit between the contact ends. With the switchelement55 tilted to provide the mercury in-the end of the space 58 and over thebarrier at circuit will be established. This barrier has its edgedepressed at its rear end so as to permit the mercury to pass thereoverand the low, point on this edge is below the abutment 60. A top part 61of the ceramic vessel is disposed over the part 59, Fig. 8. Upon anoverload being effected through the switch circuit, the mercury will beblown over the abutment 60 and will be The mercury will be lowered belowthe low point in the edge of the barrier 64. Because of the provision ofthe ceramic parts, it is unnecessary to use hydrogen in the switchelement and the switch element will be protected against excess heattending, when it occurs, to fuse the walls of the opening were it notfor the provision of the ceramic parts. If hydrogen is to be disposedwithin the chamber, it can be done very nicely by injection by a needlethrough a self-sealing sealer which will automatically seal off thechamber as the and the contact terminals 65 and 66 in place.

As shown in Fig. 12, the barrier 64 is fitted into a recess 10 in-theabutment 60 and projects rearwardly beyond the bottom part 59 of thebox. The closure plate 68 has a bottom slot ll adapted to receive therear end of the barrier 64-whereby to hold the barrier 64 againstlateral displacement.

The outer surface of the hollow portion 56 of the switch element 55 isprovided with grooves receiving respectively portions oi'wthe contactterminals 85 and' 88. Each of these. terminals have anupstanding portion.12 which extends onto-the side of thehollow portion to provide abearing I3 for engagementwith:respectively contactcstrips 28 and 21adapted to lie in the casing 2| and be secured by' screws 28 and 30respectively. 1 1

I On mounting plate .48, Fig. 6, there'is provided parallel spring wires14 having respectively .depressions 15, I8 and I1 thereinsfor receivingpointedshoulder formationsJ8.: n:

With the switch element being moved to'zthe tilted down position, asshown in. fullin Fig. 6, mercury 82 will lie in the pocket EI and'theswitch will be in the foil position If the handle 51 is lifted to locatethe shoulder 18 in the depression 15, the mercurywill be transferred tothe recess 63 and the switch will be turned on and upon thereafterbringing the pointed flange 18 to the depression 76 in the wire 14,. theswitch element will be set so that the mercury. can. be spilled over theshoulder 80-upon .an.overload current passing through the switch and so.as to break the circuit therethrough and .to lower the mercury to apoint'below the upper edge of the barrier 64. To again establishthecircuit in the switch the handle element ismoved to the on position.as shown in ,Fig. 6, and then returned to the set on,.position. Whentheswitch is lowered to the-full line position shown in Fig. 6, the.circuit controlled by the.

switch will be broken.

Referring now particularly to Figs. 13, 14 and 15, 80 represents acasing which is open at its front end and has vertically-spaced bossesBI and 82 with threaded openings for receiving screws 84 and 85respectively that secure a mounting plate 86 thereon. The rear wall ofthe casing is of arcuate shape, as indicated at 81, and has laterallyspaced radially inwardly extending guide portions 88 and 89. Betweenthese guide portions there are disposed arcuate shaped contact strips 90and 9I that extend downwardly and forwardlyand then downwardly throughopening 92 for connection with wires 93 and 94 respectively. A dependingboss 95 receives screws 96 and 91 which hold the contact terminal strips90 and 9| in place within the casing 80.

A mercury switch fuse element 98 is adjustable within the casing 80 andhas a handle portion 99 which extends outwardly through the opening inthe mounting plate 86. This element has shoulder portions I00 and IOI onthe opposite sides of the same bearing against spring wire I 02 recessedto receive the shoulders and disposed on the rear face of the mountingplate 86. On the opposite end of the element 98 are contacts I03 and I04engageable respectively with the contact terminals 90 and 9|.

The contact ends I03 and I04 are rounded so as to have smooth travelover the arcuate contact strips 90 and SI. This construction makesunnecessary the long contact terminal strips on the body of the element98 and also eliminates the need for grooves thereover.

Referring now particularly to Figs. 16 and 17, there is shown a form ofthe invention wherein the elements are adapted for operating in gangfashion or individually. According to this form of the invention, thereis provided a casing IIO having an open forward end over which is fixeda plate III having a plurality of spaced holes H2 therein. This plate issecured to the casing H0 by screws II3v disposed respectively in corneropenings II4 thereof. Extending through the rear of the casing arespring contacts H5 and I I6 which are respectively made secure on therear part of the casing by screws II! which also serve to fix wires II8respectively to these contacts. These contacts are arranged in pairs andare vertically-spaced from one another.

Mercury switch fuse elements II9 are constructed as shown in Fig. 17 andare respectively connected to a shaft I20 extending laterally from oneside of the casing to the other. These elements have a depending bossI2I through which the shaft I20 extends. A securing screw I22 is carriedby this boss and can be connected to the shaft I20 so that the shaft canbe rotated upon moving one of the elements H9 and simultaneously theother elements will be moved or, if desired, the elements can be mountedfor independent rotation on the shaft so that a selective use of theswitch elements is bad. Each ofthe elements Il9phave a handle portionI23 which extends outwardly from the front plate III.

The element I I9 is hollow and is provided with ceramic parts toovercome the rupture of the element upon overload occurring. Theseceramic parts provide a shoulder I24 and an inclined surface I25 formingthe bottom of a pocket for receiving the mercury upon overload beingeffected. Contacts I28 and I2! run out of the rear end of the elementrespectively over the bottom end faces of the elements and haverespectively stop formations I28 for receiving respectively bent endsI29 of the respective contact strips H5 and H6 to retain the element H9in either of its adjusted positions.

A barrier I30 has a depressed edge over which mercury I3I may pass toestablish the circuit between the contacts I28 and I21.

Referring now particularly to Fig. 18, there is shown an element I33constructed generally along the lines of the element 23 of Fig. 4 and ofelement 98 of Fig. 14. This element will have the usual integral handleI34 and instead of having strip contacts extending from the end of thesame, pig-tail wires I35 and I36 areembedded in .the sealingmaterialindicated at I31 and they have respectively terminal elements I38. Thesepig-tail wires permit the use of the element without the need forintervening friction contact parts.

It will now be seen that there has been pro-' vided a mercury switchconstruction wherein the mercury opening is provided in a body to whichthe handle is integrally connected and wherein the opening within thebody is lined with porcelain which is adapted to withstand heavy heatresulting from an overload in the circuit and wherein the end part ofthe porcelain and the terminals, which are extended thereinto in orderto have cont-act with the mercury, are connected and held fixed on theend of the body by a selfhardening composition.

It will also be apparent that there has been provided a simple mercuryswitch fuse element wherein the lining parts within the element bodyprovide a chamber and one of these parts is so formed as to provide anabutment separating two pockets between which the mercury can .betransferred and where there is provided in one of the pockets alongitudinally extending barrier having a lowered edge over which themercury may extend when the switch body is in the on posi- -with theterminals of the mercury element through the switch casing parts.

While various changes may be made in the detail construction, it shallbe understood that such changes shall be within the spirit and scope ofthe present invention as defined by the appended claims.

What is claimed is: v

1. A mercury switch element comprising an insulating body having anelongated opening therein, a ceramic structure provided in the openingto protect the walls of the opening from high heat which may begenerated by the mercury on an overload occurring,- said ceramicstructure including an end part, terminal strips extending through theend ceramic part and adapted to be bridged by mercury within the openingand self-hardening material extending over the end part and fixing thesame and the terminals to the switch element body, said terminals beingbent to extend in spaced relation over the edge of the body, and havingrespectively hook formations at the ends for receiving stationaryterminalsand to retain the switch body in its adjusted positions, andsaid ceramic structure having pocket openings for the collection ofmercury in the opposite ends thereof uwith an abutment lying betweenthem whereby the mercury can be effectively restrained in either end ofthe body opening.

2. A mercury switch element as defined in claim 1 and alongitudinally-extending barrier lying in one of the pocketsintermediate the sides thereof and connected between the abutment andthe end part and having a low edge portion over Which mercury may extendto provide the liquid contact between the terminals and upon the switchelement being tilted to position the mercury in the one terminal pocket.

3. A mercury switch element: as defined in claim 1 and alongitudinally-extending barrier lying in one of the pocketsintermediate the :sidesithereof and connected between the abut- "mentandthe end part and havinga low edge g-portion overywhich mercury mayextend to pro- :vi'dezthe;liquidicontact between the terminals and uponthel'switch element being tilted to poi- :sition themercury. in the oneterminal pocket and saidebutment having a. slot receiving one end of thebarrier and said end part having a 'slotrcceiving and retaining theopposite end of thebarrier. 1 I g 4. A mercury switch element as definedin claim 1 and a longitudinally-extending barrier lying in one of thepockets intermediate, the sides thereof and connected between theabutment and the end part and having a low edge portion over whichmercury may extend to provide the liquid contact between the terminalsand upon the switch element being tilted'to position the mercury in theoneterminal pocket, said switch body having a laterally-extendingopening to serve for the mounting of the switch element upon the shaftand a securing element within the body for securing the body to a shaftlying within the opening.

5. A mercury switch element comprising an insulating body having anelongated opening therein, a ceramic structure provided in the openingtoprotect the Walls of the opening from lower edges respectively of thebody and having respectively hook formations at the ends for receivingstationary terminals and to retain the switch body in its adjustedpositions. a

ISRAEL SHAMAH.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,676,754 Walker' r July 10, 1928 2,119,022 Murad May 31, 19382,248,003 Lindstrom July 1, 1941

